The EAT-Lancet Planetary Health Diet: Impact on Cardiovascular Disease and the Environment in the EPIC Cohort

BackgroundDiet plays an important role in the development of cardiovascular diseases and in maintaining sustainable planetary boundaries. The EAT-Lancet Planetary Health Diet could potentially provide co-benefits for human and environmental health, yet evidence on the association between adherence to the EAT-Lancet Planetary Health Diet and risk of cardiovascular events and environmental impact is limited. MethodsWe investigated the association between adherence to the EAT-Lancet diet and coronary heart disease (CHD) and stroke risk, and with greenhouse gas (GHG) emissions, land use, and dietary species richness (DSR). We included 364,745 adult men and women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Food frequency questionnaires were used to create a score reflecting adherence to the EAT-Lancet diet (EAT-Lancet diet-score), ranging from 0 (no adherence) to 140 (complete adherence). A (pro-) vegetarian version of the score, the EAT-Lancet dietVV-score, was also created, which rewarded low to no consumption of all animal-based foods. Cox proportional hazard regressions were used to study the association of adherence to the EAT-Lancet diet with CHD and stroke incidence. Linear regression analyzed the association with GHG emissions, land use, and DSR. FindingsOver a median follow-up of 12{middle dot}8 years, we identified 12,690 CHD and 7,088 stroke cases. After multivariable adjustment, those most adherent to the EAT-Lancet diet had lower risk of incident stroke (HRQ5vsQ1: 0{middle dot}59, 95%CI = 0{middle dot}54 to 0{middle dot}64), and of incident CHD for those younger than 60 years old at baseline (HRQ5vsQ1: 0{middle dot}86, 95%CI = 0{middle dot}79 to 0{middle dot}93). High adherence to the EAT-Lancet diet reduced GHG emissions by 1{middle dot}7% (95%CI = -1{middle dot}9 to -1{middle dot}5) and land use by 6{middle dot}2% (95%CI = -6{middle dot}4 to -5{middle dot}9). The EAT-Lancet dietVV-score further reduced GHG emissions and land use by 14{middle dot}3% (95%CI= -14{middle dot}5 to -14{middle dot}0) and 18{middle dot}8% (95%CI = -19{middle dot}0 to -18{middle dot}5), respectively, when comparing extreme quintiles, while hazard ratios for CHD and stroke remained unchanged. Those most adherent to the EAT-Lancet diet consumed 16{middle dot}1% (95%CI = 15{middle dot}9 to 16{middle dot}4) more plant species and 19{middle dot}7% (95%CI = -20{middle dot}11 to -19{middle dot}40) fewer animal species. InterpretationHigher adherence to the EAT-Lancet diet was associated with co-benefits for both cardiovascular outcomes and environmental indicators, including dietary species richness. Lower GHG emissions and land use were achieved by further reducing consumption of animal-based products. FundingThe coordination of EPIC-Europe is financially supported by the International Agency for Research on Cancer (IARC) and also by the Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London which has additional infrastructure support provided by the NIHR Imperial Biomedical Research Centre (BRC). Exposure indicators were calculated with financial support of the Wereld Kanker Onderzoek Fonds (WKOF), as part of the World Cancer Research Fund International grant programme (IIG_FULL_2020_034). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe authors considered all evidence available to them on the EAT-Lancet Planetary Health Diet, published up until May 2024. The authors searched for relevant articles on the association between adherence to the diet and cardiovascular outcomes and environmental indicators. Studies investigating the association between the diet and outcomes not of interest in this study were not considered. We restricted to evidence from prospective cohort studies with similar analyses and methodology, thereby excluding studies modelling the environmental impact. We found two research articles that explored the association of EAT-Lancet Planetary Health Diet with both cardiovascular outcomes and environmental impact, four that only assessed the association with cardiovascular outcomes, and three only focused on environmental indicators. We found no studies on the association between adherence to the EAT-Lancet Planetary Health Diet and food biodiversity. These studies spanned across varied population groups, focused on different cardiovascular endpoints and reported inconclusive evidence. This also streams from the use of different scores and indices to measure adherence to the EAT-Lancet Planetary Health Diet, which strongly influences evidence on risk estimates. Similarly, evidence on greenhouses gas emissions and land use are hindered by the use of different methodologies to calculate the associated environmental impact of foods and beverages. Added value of this studyThis study benefits from the use of a large pan-European cohort, which used a standardized nutrient and food database to determine individual dietary intake, as well as environmental data derived by Life Cycle Assessment analyses validated at the European level. The use of two diet scores--one representing an omnivorous version of the EAT-Lancet Planeatry Health Diet (EAT-Lancet diet-score) and the other representing a plant-based variation (EAT-Lancet dietVV-score) --demonstrates that greater environmental benefits can be achieved with the EAT-Lancet dietVV-score by further restricting consumption of animal-based products, without impacting the benefits on human health. The study adds to the current evidence on the impact of the EAT-Lancet Planetary Health Diet on both cardiovascular health and environmental well-being, and additionally supports evidence of an association between adherence to the EAT-Lancet Planetary Health Diet and food biodiversity. The association with food biodiversity adds an important complementary measure of health and sustainability to the current body of evidence on co-benefits of the EAT-Lancet Planetary Health Diet. Implications of all the available evidenceOur findings substantiate the co-benefits of adherence to the EAT-Lancet Planeatry Health Diet found in previous studies for cardiovascular health and environmental indicators, with evidence from a large pan-European population-based study. This research study found evidence that adherence to the EAT-Lancet diet was associated with lower risk of stroke across the whole population and with lower risk of CHD among those younger than 60 years old. This study also highlights the impact of the ways in which we operationalise adherence to the EAT-Lancet Planetary Health Diet, emphasizing its importance for comparing studies and developing national policies.